(1019) Multi-Country Trial of Intrapartum Oral Azithromycin: Cultures of Maternal Infections

Objective: An intrapartum oral dose of azithromycin (AZI) reduced maternal death or sepsis (by WHO clinical criteria). Herein, we compare the frequency of cultures, organisms and antimicrobial resistance from maternal infections by AZI vs. placebo groups.

Study Design: Ancillary study of the NICHD A-PLUS trial in which women in labor, ≥28 weeks’ and planning vaginal delivery were randomized to a 2g dose of AZI or placebo at 8 sites in 7 low- and middle-income countries (LMICs). Culture specimens from suspected infections were tested when feasible using standard of care clinical microbiological procedures at each site supplemented by AZI susceptibility testing. Cultures were encouraged for suspected sepsis (blood), cesarean or perineal wound infection, abdominopelvic or breast abscess (free pus from sites), mastitis (breast milk) and pyelonephritis (urine).

Results: Of 29,278 women randomized, 14,590 had AZI vs. 14,688 placebo. Among randomized, AZI group was associated with fewer maternal clinical cultures (any source), culture positivity, and AZI resistance (Table 1A). Among actual maternal cultures, AZI was not significantly associated with culture positivity or AZI resistance. The most prevalent organisms (Table 1B) were gram-negative rods (GNRs - E. coli and K. pneumoniae) and gram-positive cocci (GPCs - S. aureus and MRSA). GNRs and GPCs were also the most prevalent among 325 blood cultures, 168 perineal wounds and 94 cesarean wounds, while GPCs (Staph) were predominant in breast abscess and GNRs (E. coli) in pyelonephritis.

Conclusion: A single intrapartum oral dose of AZI was associated with a lower prevalence of cultures and culture-positivity in LMICs and less AZI resistant organisms.